1. Field of the Invention
The present invention relates to electric plugs, and more particularly to plugs which are self-fused.
2. Description of the Prior Art
For safety reasons it is desirable that electric plugs be fused sot that the circuit served by the plug will be broken at the plug just in case of a short circuit or overloaded condition rather than depending on the fuses or circuit breakers in the building. It is now recognized, for example, that Christmas tree light sets should be fused at an amperage rating lower than the rating of the normal home wiring circuit and fused plugs have been developed for this purpose.
Heretofore the assembly of fused plugs has involved the use of fastening devices such as screws or rivets, or the use of adhesive or other bonding techniques to secure the parts of the plug body together. It is desirable that there be ready access to the fuses in the plug for replacement, and that this access be accomplished by way of a door rather than necessitating that the plug body be disassembled. When a door is provided it should be maintained in closed position when the plug is in use, and it is advantageous to have the door remain connected to the plug body when in open position. It is preferred that the foregoing be accomplished without the need of components that cannot be molded as an integral part of the plug body and door.
For economy it is preferred to injection mold the plug body parts and the door, but the most favored thermoplastics for electric plug use are rigid and therefore not flexible. Accordingly, the design techniques commonly employed to interfit soft vinyl or rubber plug components, or relatively flexible plastic parts such as used in plastic boxes, cannot be used for rigid plastic components.